[PATCH 2 of 2] clone: check update rev for being True

[Sean Farley]

# HG changeset patch
# User Sean Farley <sean at farley.io>
# Date 1443135131 25200
#      Thu Sep 24 15:52:11 2015 -0700
# Node ID d39fa261f9d7491a3b15ca603721747904314386
# Parent  d19a61caa7c7abb23316df0458954403f2176b13
clone: check update rev for being True

In 30be3aeb5344, there was an attempt to fallback to looking up the update
revision assuming it was always a rev but the documentation states:

  True means update to default rev, anything else is treated as a revision

Therefore, we should only fallback to looking up the update rev if it is not
True. This bug was found in hg-git and I couldn't think of a test that does
this in pure Mercurial since the source repository is checked for the revision
as well (and therefore gracefully falls back).

diff --git a/mercurial/hg.py b/mercurial/hg.py
--- a/mercurial/hg.py
+++ b/mercurial/hg.py
@@ -580,14 +580,15 @@ def clone(ui, peeropts, source, dest=Non
                 status = None
                 if checkout is not None:
                     try:
                         uprev = destrepo.lookup(checkout)
                     except error.RepoLookupError:
-                        try:
-                            uprev = destrepo.lookup(update)
-                        except error.RepoLookupError:
-                            pass
+                        if update is not True:
+                            try:
+                                uprev = destrepo.lookup(update)
+                            except error.RepoLookupError:
+                                pass
                 if uprev is None:
                     try:
                         uprev = destrepo._bookmarks['@']
                         update = '@'
                         bn = destrepo[uprev].branch()